docs: def system(self):
          """returns an object to work with the site system"""
          if self._resources is None:
              self.__init()
          if "system" in self._resources:
              url = self._url + "/system"
              return _system.System(url=url,
                                    securityHandler=self._securityHandler,
                                    proxy_url=self._proxy_url,
                                    proxy_port=self._proxy_port,
                                    initialize=True)
          else:
              return None